Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3e3da5ed5034e8b4ac8370c2f3fad3f2443e531caaf36df467a13cb4a5b0d79' 
  AND token = 'R9KWmbRrPcIIDwRmOruRpyVOsNAHqmFCYbcgyaWp7FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}